PORTLAND, Maine — Selectmen in the town of Jay approved a 12.5 percent tax hike Tuesday night in anticipation that valuation of Verso Paper’s mill, the town’s largest taxpayer, would drop by more than $220 million.

Shiloh LaFreniere, Jay’s town manager, said in a phone interview Wednesday that the final valuation and amount of taxes the mill will pay are still in flux as the town completes a new appraisal at the company’s request.

“It’s based on the best information, as of [Tuesday],” LaFreniere said.

The municipal budget approved Tuesday assumes — based on a draft of the new appraisal — that the mill’s value will drop to $592 million, down from $815.4 million last year. That’s less than the $469 million abatement request the company made in February, contesting that the town’s appraiser did not use the proper techniques.

A spokesman from the company was not immediately available for comment.

LaFreniere said town officials reached an agreement with Verso to complete its revaluation process by Dec. 1 to determine a final valuation for the mill’s taxable property.

Not factoring in homestead tax exemptions, the Sun Journal reported the tax commitment approved in a 4-1 vote Tuesday will raise the tax rate 12.5 percent to $15.75 per $1,000 of assessed value. Last year’s rate for the town was $14.

The Sun Journal reported the tax rate approved Wednesday projects the Verso mill will contribute about $8.47 million, or 64 percent, of the approximately $13.2 million Jay will receive in property taxes for its 2014-2015 fiscal year.

The mill’s estimated $223 million decrease in assessed value makes up almost all of the town’s total drop in valuation of about $259.8 million, a 22 percent reduction from last year.

Memphis-based Verso has been losing money in recent quarters, posting a $43 million loss in its most recent earnings report. The company has made strides toward a deal to merge with competitor NewPage, which has a mill in Rumford. If that merger can be completed, the resulting company would become the largest single papermaker in Maine, with a combined 2,200 employees.

The company expects the merger will allow it to cut costs by about $175 million annually. In Maine, Maine Pulp and Paper Association President John Williams said in an earlier interview that the deal likely would result in some consolidation, though that would not necessarily affect either company’s Maine mills and could make the parent company more profitable.

Beyond its Bucksport and Jay mills, Verso also operates a third mill in Quinnesec, Michigan. NewPage operates the Rumford mill and seven others in Kentucky, Maryland, Michigan, Minnesota and Wisconsin.